Bridging



W. E. WHITE May 13; 1930.

BRIDGING Filed Oct. 15, 1928 Patented May 13, 1930 UNITED STATES PATENT OFFICE WILLIAM E. WHITE, OF CHICAGO, ILLINOIS, ASSIGNOB TO KALMAN STEEL COMPANY,

OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE BRIDGING Application filed October 13, 1 928.

My invention relates to means for cross connecting joists, floor beams etc., and particularly to novel means that will not only accomplish the desired result, but will add to the stability of the whole structure.

It is essential that the floor supports or joists of a building be tied together at intervals to produce a stable structure. In cases where wood joints are used, the desired result is accomplished by utilizing transverse, diagonally disposed braces that are nailed in place. In cases where metal members are employed, the problem is more difficult, the common practice being to string wires diagonally between adjacent joists and then twist the same together at their points of intersection. The rigidity of the connection and the vertical positioning of the joists are, therefore, wholly dependent on the skill and judgment of the workman; which qualities are not possessed in large measure by workmen in general. Furthermore, bridging of this character, even when skillfully applied adds but little to the sta- 2 bility of the whole structure due to the fact that it resists only such stress as may be applied tending to laterally separate onejoist from another. It has practically no resistance to compressive strains; that is, strains tending to move one joist toward another. An object of my invention is to provide a structure that may, except in isolated in stances, be prepared in the shop and installed quickly and easily by unskilled workmen with the assurance that when applied the spacing of the joists will be exactly that called for by the specifications, the integrity and resistance of each connector will be identical with that of an adjacent one; the joists in final position will be exactly vertical; the resistance of the bridging to tensile and compressive strains will be equal, and the appearance of the completed job will be neat and workmanlike.

In its simplest form, my invention contemplates a pair of cross connecting elements, each element consisting of a tension and compression member, the two elements when installed in oppositely disposed diagonal relation between a pair of joists serving to rigidly Serial No. 312,324.

unite the joists against movement either toward or away from each other.

The invention will be more readily understood by reference to the accompanying drawings, in which Fig. 1 is an elevation with the joists in section, showing my novel bridging in place;

Fig. 2 is a plan view thereof;

Fig. 3 is a perspective View, and

Fig. 4 is a sectional View on the line 14 of Fig. 1.

In the drawings, I have illustrated three joists 101112 which may be part of a series used for supporting a floor. These joists may be of truss formation, if desired, each having upper and lower chords, 1314.

The bridging of my invention comprises, essentially, a pair of elements each element consisting of a stifl and strong wire 15 having hooks 1617 at its ends and a compression member 18 preferably of angular form in cross section to add to its stiffness. These compression members preferably have notches 1920 in their respective ends, for engagement with the flanges of the chords, of adjacent trusses. The compression members of channel shape in cross section are selected for their effectiveness under compres-:

sion and for their attractiveness in appearance when in position.

The principle of operation will be apparent from the method of installation. Assuming that the truss 10 has been fixed in position and that the truss 11 is to be positioned relative thereto, a tension wire 15 is hooked over the top chord of the truss 10 and extended diagonally downward with the hook at the opposite end engaging the bottom chord of the truss 11. Thereafter, a complementary tension wire is engaged with the bottom chord of the truss 10 and the top chord of the truss 11. The truss 11 being insecurely placed may readily be moved slightly to permit engagement of the hooks therewith.

A compression strut or spreader 18 is then placed with its notched end against the lower chord of the truss l0 and close to the wire and extending diagonally away from the wire, as shown in dotted lines in Fig. 2, with its notch 20 in engagement with the top chord of the truss 11. The spreader is in this position due to the factthat the distance between the respective chords is at that time slightly less than the effective length of the strut. However, by applying force, as with a hamn er, to the end that is out 01? position, the strut may be driven into parallelism with the ten sion wire by sliding the abutting notched surface along the edge of the chord. This will place the wire under relatively high tension and serve to effect a tirm and rigid holding action. This operation is then repeated with the complementary diagonally disposed tension and compression members with a resulting structure as shown in the drawings. If a channel shaped strut is used, the tension wire will preferably be contained within the channel and the resulting structure will be a bridging that will be neat and attractive and add materially to the structural strength of the design.

If desired, the compression members may be joined at the point of intersection in which case, they must be applied as a unit and driven in place together. In this construction, the tension wires and the struts must lie in slightly different vertical planes.

The elements composing the bridging may be constructed accurately in the shop with the assurance that the workmen cannot install improperly. In cases where an unusual or accidental spacing of the joists occurs, provision will be made on the job for the construction by hand in a simple manner of bridging elements that will efi'ect the desired result in the manner described.

While I have illustrated a tension wire having hooks for engaging the chords of the trusses, it will be understood that l contemplate the use of any similar tension means, such as wires wrapped around the chords.

t will be understood also that the cross sectional form of the spreaders or struts is unimportant, the only requirement being that they shall possess sullicient resistance to lateral bending to supply the required stillness.

I claim:

1. In bridging for beams, the con'ibination of a tension member adapted to be united to a pair of spaced beams and a separate compression member adapted to abut said beams at points adjacent to the points of engagement therewith of the tension members and to be forced from a non-parallel position into parallelism with the tension member by sliding one end along the abutting surface of the member on the beam.

2. In bridging, the combination of a tension member adapted to extend diagonally between the upper chord of one member and the lower chord of an adjacent member, and a spreader adapted to engage the said chords, said spreader being of slightly greater length than the space separating said chords at the time of installation of the tension members whereby said spreader must be driven into position to place the tension member under tension.

3. in bridging, the combination of a tension member adapted to extend between and be secured to the chords or" a pair of spaced beams, and a spreader adapted to engage said chords, said spreader being of great r length than the space separating said chords at the time of installation of the tension members, and being adapted to be driven into final position and to force said beams apart by wedge action.

4. The combination with joists having chords of a pair of wires having hooked ends engaging the upper and lower chords of said pair of joists and arranged in diagonal relation intersecting at a point midway between their ends, and compression struts having notched ends adapted to engage said chords and to be forced from an angular position into parallelism with said wires.

5. The combination with joists having chords, of a relatively stitl wire having hooks on its ends adapted to respectively engage the upper and lower chords of said pair of joists, and a compression strut having a notch in one end adapted to engage one of said chords adjacent to the point of engagement of the wire therewith, the effective length oi said strut being slightly greater than the distance separating said chords at the time of installation of the wire, said strut being adapted to be forced into final position by wedge action whereby the joists are forced apart and tension is placed upon said wire.

6. The combination with joists having chords of a wire having hooks on its ends and adapted to extend diagonally from the u iper chord on one joist to the lower chord of an adjacent joist and to resist tension stresses and a separate compression strut of angular cross-section having notches in its ends and adapted to engage said chords and to be of such length relative to the space between the respective chords as defined by said tension wire that when forced into position the strut is under initial compression and the wire under initial tension.

In testimony whereof I have affixed my signature.

WILLIAM E. lVHITE. 

